新疆萨吾尔地区扎合岩体地球化学特征及构造意义

Geochemical Characteristics and Tectonic Significance of Zhahe Rock Mass in Sawu er Area,Xinjiang

扎合岩体位于哈萨克斯坦准噶尔板块北缘,属于萨吾尔晚古生代岛弧带,岩石类型以花岗闪长岩为主。笔者通过对该岩体的岩石地球化学、岩石类型、岩浆源区、构造背景研究表明,扎合岩体属于钙碱性系列侵入岩,在岩浆演化过程中没有明显的分离结晶作用且分异程度不高,暗示其原始岩浆的来源可能为上地幔,形成环境为后碰撞阶段的挤压环境;扎合岩体地球化学特征的确定为晚古生代西准噶尔地区地壳的垂向增生以及后碰撞岩浆活动的研究提供了新的证据。

Zhahe rock mass is located in the northern margin of the Kazakhstan-Junggar plate,belonging to the Sawu er island arc belt of late Paleozoic.And the rock type is mainly granodiorite.Based on a study of rock geochemistry,rock type,magma source area and tectonic setting,the authors found that the Zhahe rock mass was the calc-alkaline intrusive rocks.There was no obvious separation crystallization in the magmatic evolution process and the differentiation degree was not high,suggesting that the original magma may come from the upper mantle and the compression environment in the post-collision stage.Zhahe geochemical characteristics provide new evidence for the study of the vertical crustal accretion and the post-collisional magmatic activities in the late Paleozoic in western junggar.